Highly conformal hypo-fractionated image guided radiotherapy is an emerging technically complex method for precision irradiation of stage 1 NSCLC using doses with a higher biological effect than can be achieved with standard treatment techniques. Although rates of local control using hypo-fractionation appear greater, there are risks with serious late toxicity. However, there is recent evidence that 54-57Gy delivered in 3 fractions can be delivered safely with no excessive toxicity, provided the tumour has a peripheral location, the chest wall is not included in the high dose volume and the treatment plan is highly conformal. Although hypo-fractionation under the above conditions appears to be tolerable, and is associated with high levels of local control, the results of a small number of phase II trials cannot be regarded as sufficient evidence to recommend it as the standard of care for inoperable stage I NSCLC.